Site migration to orchard: Need Advices

In my current job I've been given the task of finding an ASP .NET CMS to migrate (port) all the current sites that are made with Wordpress and other PHP CMSs. After reading and evaluating different CMSs I choosed Orchard to start our migration pilot.

The site I'm currently trying to implement in Orchard is:
http://www.losmolinos.com.co/
It is an intermediate project: Not too easy, not too hard. There are more complex projects in the company I'm working.

Although I've read a lot about Orchard and have followed a few tutorials, there is a lot I must be missing out right now and here is where your help comes in! :)

Do you think this kind of sites (white so much design) are achievable with Orchard?

Should I start by modifying The Theme Machine or should I start from scratch trying to build my theme for sites like this?

Any othere advices are received with joy

I let you know if anything else comes to my mind while I keep reading and trying my best to start this journey!